This invention relates to degradation resistant polyolefin articles including filaments, fibers, films, sheets, and the like. In accordance with another aspect, this invention relates to degradation resistant polyolefin articles which contain a stabilizing system comprising a hindered amine and a metal phosphonate which are overcoated with a finish composition comprising an ethoxylated compound and a phosphate ester. In accordance with another aspect, textile materials formed from polymers of propylene containing a stabilizing system are overcoated with a finishing composition comprising an ethoxylated textile lubricant and a phosphate ester antistatic agent to impart antistatic properties and increase the thermal stability of the textile materials.
In the formation of textile materials from melt spun polypropylene it is normally necessary to apply a finishing composition to the filaments, yarns and other textile embodiments thereof to make such materials more amenable to the various operations to which they are subjected during processing, for example, spinning, winding, yarn-forming, weaving, knitting, etc., and to improve the properties of the finished products. In the processing of the textile materials, the finishing composition is intended to reduce friction between the yarn and various pieces of equipment with which it comes into contact, such as guides, rollers and the like, and in both the processing and use of the textile materials to reduce friction between the fibers themselves, to prevent fiber and yarn breakage and to minimize excessive attraction or repulsion of the filaments caused by electrostatic charges. Accordingly, such finishing compositions usually contain a lubricant and an antistatic agent. Various other additives such as bactericides, corrosion inhibitors, etc., may also be added to the finishing composition.
However, it has been found that not all thermoplastic materials respond to finishing compositions in the same manner, not all combinations of finishing agents are compatible with one another and not all finishing agents are compatible with stabilizers and the like added to the thermoplastic melt. Specifically, it has been found, in accordance with the present invention, that polypropylenes do not respond to certain lubricants in the same manner as other thermoplastic fiber-forming materials, particularly when the polypropylenes contain less than the normal amounts of stabilizing agents, such as antioxidants, or when they contain specific types of stabilizing agents. By less than normal amounts of stabilizers is meant polypropylene containing from about 0.1 to about 0.6 weight percent total stabilizers. It has also been found that certain textile lubricants have an antagonistic effect on certain stabilizers included in polypropylene melts.
Accordingly, an object of this invention is to provide degradation resistance to polyolefin articles.
Another object of this invention is to provide polyolefin articles overcoated with a finishing composition providing antistatic and thermal stability properties to the articles.
Another object of this invention is to provide a stabilizing system and a finishing composition for polyolefin articles that are compatible.
Other objects, aspects as well as the several advantages of this invention will be apparent to those skilled in the art upon reading this specification and the appended claims.